退火对MgxZn1-xO薄膜特性的影响

采用MOCVD法在c面蓝宝石衬底上生长出了高质量的MgxZn1-xO薄膜. 研究了退火对MgxZn1-xO薄膜各种特性的影响. 将样品分别在真空和氧气中退火1 h. X射线衍射研究发现, 在真空中, 尤其是在氧气中退火的样品的(002)峰均增强. 由原子力显微镜观察发现, 在真空中退火样品的表面与未退火样品的表面几乎相同, 而在氧气中退火后样品的表面变得光滑了很多. 从光致发光光谱中发现, 真空退火后的样品的紫外光谱峰显著增强, 而深能级发射峰几乎消失. 在氧气中退火后样品的紫外光谱峰减弱而深能级发射峰显著增强. 所以退火对MgxZn1-xO薄膜的各种性质具有重要的影响, 通过退火可调节MgxZn1-xO的晶体质量与光学质量.     

Photoluminescence Properties of Two-dimensional Planar Layer and Three-dimensional Island Layer for ZnO Films Grown Using MOCVD

IntroductionOver the past few years, wide band gap semicon-ductors have attracted considerable attention because oftheir high commercial demand for the preparation ofblue and UV light emitters. The most promising amongall the known materials used for this…     

Influence of Annealing on Properties of ZnO Films Grown via Plasma－enhanced MOCVD

The structural and the optical properties of ZnO films with high quality grown via plasma-enhanced met-al-organic chemical vapour deposition(MOCVD) on C-plane sapphire substrate were studied. The crystallini-ty and the optical properties of the films are greatly improved having been annealed in oxygen plasma atmo-sphere. The structure, the band gap and the binding energy of O1s electrons, and the molar ratio of O to Zn were determined by X-ray diffraction (XRD), photoluminescence (PL) and X-ray photoelectron scan meth-ods. For both the annealed and the as-grown films, the exciton peak features were observed at room temper-ature. The band-edge photolof the annealed film is much stronger than that of the as-grown film, and the exciton peak relating to the deep level at 439 nm disappears. The molar ratio of O to Zn in the annealed film is 0. 91, while it is 0. 78 for the as-urown film.     

声表面波器件用〈110〉取向ZnO薄膜的MOCVD生长

Zn O是具有纤锌矿晶体结构的多功能半导体材料 ,它具有 3 .3 7e V的禁带宽度和高达 60 me V的激子束缚能 ,是很有希望的紫外发光材料 .由于具有 c轴的择优取向性 ,因此目前人们的注意力主要集中在对 c轴取向 Zn O薄膜的特性研究上 [1～ 3] .但其它取向的 Zn O薄膜也可在某些衬底的特定面上 ,通过特定的条件进行生长 ,如〈1 1 0〉取向的 Zn O薄膜可在特定的条件下生长在蓝宝石 R面衬底上[4～ 7] .由于 (1 1 0 )面的 Zn O薄膜具有一些 c轴取向薄膜所不具备或无法比拟的特性 ,如 :机电耦合系数高达6% (C面薄膜的机电耦合系数却不足 1 % )…     

金属有机化学气相沉积法制备ZnO和ZnO∶Ni薄膜及其特性分析

采用金属有机化学气相沉积法制备了ZnO和ZnO∶Ni薄膜,并对它们的结构、光学和电学特性进行了对比研究.通过扫描电子显微镜( SEM)和X射线衍射(XRD)对薄膜的表面形貌和晶体结构进行了分析,结果表明,Ni元素的掺杂虽然降低了薄膜的晶体质量,但并未改变ZnO的纤锌矿结构.通过紫外-可见分光光度计对薄膜的光学特性进行了...     

溶胶-凝胶法制备的MgxZn1-xO纳米薄膜结构和光学性质

用溶胶-凝胶法制备了不同组分的Mg_xZn_1-xO薄膜.X射线衍射结果表明,薄膜为具有六角纤锌矿结构的纳米薄膜,晶粒尺寸3～5nm,随着Mg进入ZnO晶格,其晶格常数变小.紫外-可见吸收光谱表明,随着Mg含量的增加带隙变宽,自由激子吸收峰明显蓝移.室温光致发光光谱由很强的且与氧空位相关的深能级缺陷发光和较弱的紫外激子发光组成,激子发光强度和缺陷发光强度比随x的增大而减小,表明Mg原子进入ZnO晶格会引起深能级缺陷的增加.Mg_0.03Zn_0.97O薄膜经700℃热氧化后,紫外与可见发光强度比达到30.     

Structural and Optical Properties of ZnO Films with Different Thicknesses Grown on Sapphire by MOCVD

IntroductionZnOis one of the most promising materials for pro-ducing ultraviolet laser at room temperature because ofits wide direct band gap(Eg=3.37eV)and large ex-citonic binding energy of60meV.Recently,much at-tention has been paid to short-wavelength …     

溅射参数对ZnO薄膜物性的影响

采用磁控溅射方法分别在ITO玻璃和硅片上成功制备了具有良好C轴取向的ZnO薄膜.并研究了溅射气压,基底温度,以及氧偏压对ZnO薄膜物性的影响,从而确定了制备ZnO薄膜的最佳溅射条件.     

Deposition Mechanism and Properties of Plasma-Enhanced Atomic Layer Deposited Gallium Nitride Films with Different Substrate Temperatures

Gallium nitride (GaN) is a wide bandgap semiconductor with remarkable chemical and thermal stability, making it a competitive candidate for a variety of optoelectronic applications. In this study, GaN films are grown using a plasma-enhanced atomic layer deposition (PEALD) with trimethylgallium (TMG) and NH₃ plasma. The effect of substrate temperature on growth mechanism and properties of the PEALD GaN films is systematically studied. The experimental results show that the self-limiting surface chemical reactions occur in the substrate temperature range of 250–350 °C. The substrate temperature strongly affects the crystalline structure, which is nearly amorphous at below 250 °C, with (100) as the major phase at below 400 °C, and (002) dominated at higher temperatures. The X-ray photoelectron spectroscopy spectra reveals the unintentional oxygen incorporation into the films in the forms of Ga₂O₃ and Ga-OH. The amount of Ga-O component decreases, whereas the Ga-Ga component rapidly increases at 400 and 450 °C, due to the decomposition of TMG. The substrate temperature of 350 °C with the highest amount of Ga-N bonds is, therefore, considered the optimum substrate temperature. This study is helpful for improving the quality of PEALD GaN films.     

溶胶-凝胶法在聚酰亚胺衬底上制备c轴取向ZnO薄膜

通过溶胶-凝胶工艺, 采用两步加热法在聚酰亚胺表面制备了具有c轴取向的ZnO薄膜. 通过差式扫描量热-热重分析(DSC-TGA)得出最佳的前热处理温度和后热处理温度分别为300和390 ℃. 通过X射线衍射(XRD)和扫描电子显微镜(SEM)对薄膜的晶体取向和表面形貌进行了分析, 描述了ZnO薄膜在聚酰亚胺上的生长过程. 拉伸实验结果表明, ZnO薄膜与聚酰亚胺衬底有较强的附着力.     

Effect of Doped Boron on the Properties of ZnO Thin Films Prepared by Sol-gel Spin Coating

Transparent conductive boron-doped ZnO thin films were prepared by sol-gel spin coating method. The effect of doped boron concentration on the properties of the films was systematically discussed. The films were characterized by X-ray diffraction, atomic force microscopy, spectrophotometry, and Hall effect measurement system. All the doped and undoped ZnO films were of a single hexagonal structure, and showed a preferred orientation of （002）. The particle size and surface roughness of the films decreased with increased doped boron concentration. All the films exhibited an average transmittance of approximate 90% in visible-light region and an energy gap of about 3.3 cV. The maximum carrier concentration, the highest carrier mobility and the lowest resistivity were observed at a doped boron concentration of 0.5%（molar fraction）. Based on these results, we suggested that the saturation concentration of doped boron in ZnO film is 0.5%（molar fraction）.     

Atomic Force Microscopy Studies of SnO2 Thin Film Microstruc tures Deposited by Atomic Layer Epitaxy

 ALE-grown, rutile-type SnO₂ thin films and gas sensor structures based thereupon were studied by AFM with main emphasis on cross-sectional investigations (X-AFM). On glass substrates the polycrystalline films showed a preferred orientation which depended on the film thickness and growth temperature while on single crystal sapphire () the growth was heteroepitaxial. For the X-AFM studies various sample preparation techniques were investigated but only ion beam etching gave satisfactory results and revealed substructures in the sensor structure consisting of Pt and SnO₂ layers on a silicon substrate.     

不同金属缓冲层对GaN薄膜的光学及电学性能的影响

本文以金属Ga和NH₃为原料,Al、Ni和Fe为金属缓冲层,采用化学气相沉积法(CVD)在Si(100)衬底上合成了GaN微米薄膜。利用X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、能量弥散X射线谱(EDS)、光致发光光谱(PL)和霍尔效应测试仪(HMS-3000)等对GaN微米薄膜进行表征。结果表明,所有样品均为六方纤锌矿结构;样品均出现了很强的近带边紫外发射峰和半峰宽较大的中心波长为672nm红光发射峰;不同样品的电学性能差异较大。最后对合成的GaN微米薄膜的可能形成机理进行了简单分析。     

不同金属缓冲层对GaN薄膜的光学及电学性能的影响

本文以金属Ga和NH3为原料,Al、Ni和Fe为金属缓冲层,采用化学气相沉积法(CVD)在Si(100)衬底上合成了GaN微米薄膜。利用X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、能量弥散X射线谱(EDS)、光致发光光谱(PL)和霍尔效应测试仪(HMS-3000)等对GaN微米薄膜进行表征。结果表明,所有样品均为六方纤锌矿结构;样品均出现了很强的近带边紫外发射峰和半峰宽较大的中心波长为672 nm红光发射峰;不同样品的电学性能差异较大。最后对合成的GaN微米薄膜的可能形成机理进行了简单分析。     

Crystallization Behavior and Properties of B-Doped ZnO Thin Films Prepared by Sol-Gel Method with Di erent Pyrolysis Temperatures

Boron-doped zinc oxide transparent (BZO) films were prepared by sol-gel method. The effect of pyrolysis temperature on the crystallization behavior and properties was systematically investigated. XRD patterns revealed that the BZO films had wurtzite structure with a preferential growth orientation along the c-axis. With the increase of pyrolysis temperature, the particle size and surface roughness of the BZO films increased, suggesting that pyrolysis temperature is the critical factor for determining the crystallization behavior of the BZO films. Moreover, the carrier concentration and the carrier mobility increased with increasing the pyrolysis temperature, and the mean transmittance for every film is over 90% in the visible range.     

Studies on the Structure of Gel during Preparing ZnO Thin Films by Sol-gel Method

<正>Transparent thin films of ZnO have been prepared on ordinary glass substrates by the inorganic sol-gel method using citric acid as chelating agent and zinc nitrate as the starting material.A novel structure on zinc citrate complex was put forward by using DTA-TG and FT-IR absorbance spectrum of citrate gels.Phase formation,morphology and optical properties of ZnO films are investigated by XRD,AFM and UV-vis transmittance spectra.The experimental results show that ZnO thin films derived from zinc citrate sol-gel method showed a(002)oriented hexagonal wurtzite structure,good crystalline property,a uniform range of grain size(40 nm), smooth surface of films,band gap of 3.28 eV and optical transmittances ratio over 90%in the visible range.     

反应溅射法在立方织构镍基底上制备CeO2缓冲层

采用反应溅射的方法在具有立方织构的Ni基底上制备了 CeO2缓冲层.以Ar/H2混合气体为预沉积气体,有效地抑制了基底的氧化.在基片温度为650 ℃,气压为26 Pa的条件下沉积的CeO2薄膜具有纯c轴取向.X射线θ-2θ扫描、极图分析、Φ扫描结果表明,CeO2薄膜有良好的立方织构,其Φ扫描半高宽(FWHM)为9.0°.扫描电镜观察表明,薄膜致密且没有裂纹.     

ZrxCe1－xO2催化剂催化湿式氧化乙酸的活性研究

采用共沉淀法制备了Zr_xCe_1－xO₂催化剂, 利用BET, XRD和XPS对其进行了表征, 并研究了催化剂催化湿式氧化乙酸的活性. 结果表明: Zr和Ce摩尔比为1∶9的催化剂催化湿式氧化乙酸时具有最好的活性, 当乙酸溶液的初始化学需氧量(COD)为5000 mg/L, 反应温度为230 ℃, 压力为5 MPa时, 120 min后, COD的去除率为76% . 催化剂具有良好的活性是因为在CeO₂中加入Zr能够增大催化剂的比表面积和表面缺陷氧的含量, 并最终加快了HO₂•自由基的产生, 从而提高了催化剂的活性.     

射频溅射制备的多晶ZnO膜表面氧的吸附和脱附

多晶的六角密排的ｃ轴平行于衬底的ＺｎＯ膜已用射频溅射的方法制备出来，一电场感应的氧吸附在这些膜上被观察到由紫外光照射或与Ａｒ离子反应所产生的氧的脱附可使膜的电导率增加６－７个数量级，并且一个积累层在膜的表面显现出来。     

磁控溅射中靶-基底距离与Si共掺对ZnO:Al薄膜性质的影响

使用射频磁控溅射, 在正方形石英衬底上沉积透明导电掺Al的ZnO(AZO)和Si共掺AZO(AZO:Si)薄膜. 系统研究了靶-基底距离(D_st)和Si共掺对AZO薄膜电学、光学性质的影响. 电阻率、载流子浓度和迁移率都强烈地依赖于靶-基底距离, 随着靶-基底距离的减少, 载流子浓度和迁移率都有显著的增加, 电导率也随之提高. 在靶-基底距离为4.5 cm处, 得到最低电阻率4.94×10^-4 Ω·cm, 此时的载流子浓度和迁移率分别是3.75×10²⁰ cm^-3和33.7 cm²·V^-1·s^-1. X射线光电子能谱(XPS)、X射线衍射(XRD)和边界散射模型被用于分析载流子浓度、迁移率和靶-基底距离的关系. 透射谱显示, 在可见-近红外范围内所有样品均有大于93%的平均透射率, 同时随着靶基距离的减少, 吸收边蓝移. AZO:Si表现出可与AZO相比拟的高电导和高透射光学特性, 但在热湿环境中却有着更好的电阻稳定性, 这在实际使用中很有意义.